Low end, high end, in the end I've decided to forego a new bike and do a partial rebuild in the Nishiki. There are other things I'd like to do with the few bucks I have. The price he quoted me for the things I want to do make it a better deal at $300 than a new bike with newer technology and the only complaints I have with this bike will be remedied with the partial rebuild.
As for the cassette, it has a 5 speed cassette already. Even though we have primarily flats, I'd like to be able to tackle at least the hills of North Florida. I'm keeping this bike. I guess bikes are personal things.